JPH02268271A - Method and apparatus for quantitative analysis of isolated acid and metal ion in solution - Google Patents
Method and apparatus for quantitative analysis of isolated acid and metal ion in solutionInfo
- Publication number
- JPH02268271A JPH02268271A JP9025089A JP9025089A JPH02268271A JP H02268271 A JPH02268271 A JP H02268271A JP 9025089 A JP9025089 A JP 9025089A JP 9025089 A JP9025089 A JP 9025089A JP H02268271 A JPH02268271 A JP H02268271A
- Authority
- JP
- Japan
- Prior art keywords
- solution
- metal ion
- titration
- acid
- amount
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000002253 acid Substances 0.000 title claims abstract description 67
- 229910021645 metal ion Inorganic materials 0.000 title claims abstract description 45
- 238000000034 method Methods 0.000 title claims description 14
- 238000004445 quantitative analysis Methods 0.000 title claims description 6
- 238000004448 titration Methods 0.000 claims abstract description 41
- 239000003638 chemical reducing agent Substances 0.000 claims abstract description 24
- 239000012488 sample solution Substances 0.000 claims abstract description 16
- 238000010521 absorption reaction Methods 0.000 claims abstract description 11
- 238000005259 measurement Methods 0.000 claims abstract description 6
- 239000003513 alkali Substances 0.000 claims abstract description 3
- 238000006722 reduction reaction Methods 0.000 claims description 22
- 238000002835 absorbance Methods 0.000 claims description 16
- 238000006386 neutralization reaction Methods 0.000 claims description 14
- 150000007513 acids Chemical class 0.000 claims description 10
- 238000001514 detection method Methods 0.000 claims description 5
- 238000000954 titration curve Methods 0.000 claims description 5
- 238000012545 processing Methods 0.000 claims description 4
- 238000004313 potentiometry Methods 0.000 claims description 3
- 238000012937 correction Methods 0.000 claims description 2
- 239000000243 solution Substances 0.000 abstract description 51
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 12
- 238000004458 analytical method Methods 0.000 abstract description 7
- 238000006243 chemical reaction Methods 0.000 abstract description 5
- 239000012895 dilution Substances 0.000 abstract description 4
- 238000010790 dilution Methods 0.000 abstract description 4
- 239000007789 gas Substances 0.000 abstract description 3
- 239000000523 sample Substances 0.000 abstract description 3
- 239000011261 inert gas Substances 0.000 abstract description 2
- 239000000203 mixture Substances 0.000 abstract description 2
- 238000011068 loading method Methods 0.000 abstract 1
- 230000007935 neutral effect Effects 0.000 abstract 1
- 230000003647 oxidation Effects 0.000 abstract 1
- 238000007254 oxidation reaction Methods 0.000 abstract 1
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 45
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 45
- 229910052742 iron Inorganic materials 0.000 description 26
- -1 iron ions Chemical class 0.000 description 24
- 238000005554 pickling Methods 0.000 description 16
- PPASLZSBLFJQEF-RKJRWTFHSA-M sodium erythorbate Chemical compound [Na+].OC[C@@H](O)[C@H]1OC(=O)C(O)=C1[O-] PPASLZSBLFJQEF-RKJRWTFHSA-M 0.000 description 13
- 235000010352 sodium erythorbate Nutrition 0.000 description 13
- 239000007864 aqueous solution Substances 0.000 description 9
- AKHNMLFCWUSKQB-UHFFFAOYSA-L sodium thiosulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=S AKHNMLFCWUSKQB-UHFFFAOYSA-L 0.000 description 7
- 235000019345 sodium thiosulphate Nutrition 0.000 description 7
- 238000007796 conventional method Methods 0.000 description 6
- 239000012670 alkaline solution Substances 0.000 description 5
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 238000007664 blowing Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- CEQFOVLGLXCDCX-WUKNDPDISA-N methyl red Chemical compound C1=CC(N(C)C)=CC=C1\N=N\C1=CC=CC=C1C(O)=O CEQFOVLGLXCDCX-WUKNDPDISA-N 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 229910052708 sodium Inorganic materials 0.000 description 2
- 239000011734 sodium Substances 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- SBJKKFFYIZUCET-JLAZNSOCSA-N Dehydro-L-ascorbic acid Chemical compound OC[C@H](O)[C@H]1OC(=O)C(=O)C1=O SBJKKFFYIZUCET-JLAZNSOCSA-N 0.000 description 1
- DWAQJAXMDSEUJJ-UHFFFAOYSA-M Sodium bisulfite Chemical compound [Na+].OS([O-])=O DWAQJAXMDSEUJJ-UHFFFAOYSA-M 0.000 description 1
- 229910001420 alkaline earth metal ion Inorganic materials 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 239000002738 chelating agent Substances 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 229940079827 sodium hydrogen sulfite Drugs 0.000 description 1
- 235000010267 sodium hydrogen sulphite Nutrition 0.000 description 1
- 238000002798 spectrophotometry method Methods 0.000 description 1
Landscapes
- Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
- Investigating Or Analysing Materials By The Use Of Chemical Reactions (AREA)
Abstract
Description
【発明の詳細な説明】
〈産業上の利用分野〉
本発明は、酸の当量点と滴定終点が重複する金属イオン
を含有する溶液中の遊離酸および金属イオンを連続的に
定量する方法および装置に関する。Detailed Description of the Invention <Industrial Application Field> The present invention provides a method and apparatus for continuously quantifying free acid and metal ions in a solution containing metal ions whose acid equivalence point and titration end point overlap. Regarding.
〈従来の技術〉
溶液中の遊離酸および金属イオンを定量することは、生
産管理上重要である。<Prior Art> Quantifying free acids and metal ions in a solution is important for production control.
特に、鋼板上のスケールを効率良く除去するため、酸洗
液中の遊１１１酸および金属イオン濃度を把握すること
が要求されている。 これは、酸洗処理量の増加に伴
い、酸洗液中の酸は消費され、酸洗能力が低下すること
、酸の補充が過多となると、酸量増加によるコストの増
加、鋼板表面の浸食による製品の品質低下を招くことに
よる。 また、酸洗に伴う酸洗液中の金属イオン量の増
加により、酸洗能力が低下するため、酸洗液中の金属イ
オン濃度も管理する必要がある。In particular, in order to efficiently remove scale on steel plates, it is required to understand the free 111 acid and metal ion concentrations in the pickling solution. This is because as the amount of pickling increases, the acid in the pickling solution is consumed and the pickling ability decreases.If too much acid is replenished, costs increase due to the increased amount of acid and corrosion of the steel plate surface occurs. This may lead to deterioration of product quality. Furthermore, since the pickling ability decreases due to an increase in the amount of metal ions in the pickling solution due to pickling, it is also necessary to control the metal ion concentration in the pickling solution.
酸も金属イオンもアルカリ滴定により、分析することが
可能であることを利用し、塩酸あるいは硫酸酸洗液中の
遊離酸および鉄イオン同時分析法が報告されている（特
公昭５６−３９７１４）。 この場合、酸洗液中の鉄イ
オンは大部分が２価で存在するため、酸の滴定終点との
分離は容易である。 しかし、硝酸酸洗液等の酸化性の
溶液では、鉄イオンは３価で存在する場合が多く、アル
カリ土類金属イオン加水分解時のＰ）（が酸の滴定終点
ｐＨと接近しており、酸の終点と重複する。 したが
って、中和滴定による酸分析では、Ｆｅ’＋等の金属イ
オンの影響を除くため、あらかじめこれらの金属イオン
を除去するか、あるいは、適当なキレート剤を用いて金
属イオンをマスクする必要があった。Utilizing the fact that both acids and metal ions can be analyzed by alkaline titration, a method for simultaneous analysis of free acids and iron ions in hydrochloric acid or sulfuric acid pickling solutions has been reported (Japanese Patent Publication No. 56-39714). In this case, since most of the iron ions in the pickling solution exist in divalent form, it is easy to separate them from the acid titration end point. However, in oxidizing solutions such as nitric acid pickling solutions, iron ions often exist in trivalent form, and P) (at the time of alkaline earth metal ion hydrolysis) is close to the titration end point pH of the acid. Therefore, in acid analysis by neutralization titration, in order to eliminate the influence of metal ions such as Fe'+, these metal ions must be removed in advance, or metal ions must be removed using an appropriate chelating agent. It was necessary to mask the ions.
そこで、酸の滴定終点と重複するＦｅ”をチオ硫酸ナト
リウムを用いて下式に示すように、Ｆｅ２ゝに還元し、
終点ｐＨを変更して遊離酸と鉄イオンをアルカリ滴定で
同時に分析する方法が報告されている（片桐ら 計装
ｖｏｌ。Therefore, Fe'', which overlaps with the acid titration end point, is reduced to Fe2゜ using sodium thiosulfate as shown in the formula below,
A method has been reported in which free acid and iron ions are simultaneously analyzed by alkaline titration by changing the end point pH (Katagiri et al.
vol.
２９ Ｎｏ２ ｐ、１３ １９８６）。29 No. 2 p. 13 1986).
２ Ｆ ｅ”＋ ２３． Ｏ，” −４２Ｆ ｅ ”＋
３４０ 、’−
しかし、この方法では、第１表に示すように、還元剤の
添加量が酸および金属イオン定量値に影響を与える。2 F e"+ 23. O," -42F e "+
340,'- However, in this method, as shown in Table 1, the amount of reducing agent added affects the quantitative values of acid and metal ions.
第
表
（ｍ ｏ ｌ ／ ｊ！ ）
すなわち、チオ硫酸ナトリウム量が不足するとＦｅ３＋
の還元が不十分となり、残留Ｆｅ”が酸の当量点と重複
するため、酸濃度定量値が高くなる。 また、チオ硫
酸ナトリウムを過剰に添加すると、下式の反応により、
チオ硫酸ナトリウムと酸が反応し、酸の定量値が低値を
示す。Table (mol/j!) In other words, if the amount of sodium thiosulfate is insufficient, Fe3+
The reduction of the residual Fe is insufficient, and the residual Fe overlaps with the acid equivalence point, resulting in a high quantitative acid concentration value.Also, if sodium thiosulfate is added in excess, the following reaction will occur:
Sodium thiosulfate and acid react, and the quantitative value of the acid shows a low value.
５２０３’−＋２’Ｈ”→Ｓｏ２＋Ｓ＋Ｈ２０〈発明が
解決しようとする課題〉
前記の片桐らの方法では、滴定終点が酸の当量点と重複
する金属イオンの還元剤添加量が不足すると還元が不十
分となり、また、過剰に添加すると酸との反応により、
遊離酸および金属イオンの測定値に誤差が生じるため、
金属イオン濃度に対応して適正な還元剤量を添加する必
要があり、溶液中に含まれる金属イオン濃度をあらかじ
め測定しておかなければならないという問題があった。5203'-+2'H"→So2+S+H20 <Problem to be solved by the invention> In the method of Katagiri et al., reduction is insufficient if the amount of reducing agent added for metal ions whose titration end point overlaps with the acid equivalence point is insufficient. Also, when added in excess, due to reaction with acid,
Due to errors in measurements of free acids and metal ions,
There was a problem in that it was necessary to add an appropriate amount of reducing agent in accordance with the metal ion concentration, and the metal ion concentration contained in the solution had to be measured in advance.
本発明は、以上の問題点を解決し、溶液中の遊離酸およ
び金属イオンを正確に連続分析する方法およびその装置
を提供することを目的とする。An object of the present invention is to solve the above problems and provide a method and apparatus for accurately and continuously analyzing free acids and metal ions in a solution.
く課題を解決するための手段〉
本発明の第１の態様によれば、滴定終点が酸の当量点と
重複する金属イオンを含む溶液において、吸光度検出法
または電位差測定法により、金属イオンの還元反応の完
了を検知し、還元剤の添加量から金属イオン濃度を求め
た後、中和滴定によりｔｌＩＩＩｌｔ酸濃度を求めるこ
とを特徴とする溶液中の遊離酸および金属イオンの連続
定量分析法が提供される。Means for Solving the Problems> According to the first aspect of the present invention, in a solution containing metal ions whose titration end point overlaps with the acid equivalence point, the reduction of metal ions is carried out by absorbance detection method or potentiometry method. Provided is a continuous quantitative analysis method for free acid and metal ions in a solution, which is characterized in that after detecting the completion of the reaction and determining the metal ion concentration from the amount of reducing agent added, the tlIIIlt acid concentration is determined by neutralization titration. be done.
本発明の第２の態様によれば、吸光光度計または電位差
計および酸濃度測定装置が付設された試料溶液の希釈装
置と、吸光光度計または電位差計により測定される吸光
度または電位の変動から金属イオンの還元剤の添加量を
制御する還元剤添加装置と、酸濃度測定装置により測定
される酸濃度の変動からアルカリ滴定量を制御する滴定
製蓋と、滴定曲線から試料溶液中の各成分の定量値計算
、補正計算を行うデータ処理装置とを具えることを特徴
とする溶液中遊離酸および金属イオンの定量分析装置が
提供される。According to a second aspect of the present invention, there is provided a sample solution diluter equipped with an absorption photometer or potentiometer and an acid concentration measuring device, and a metal A reducing agent addition device that controls the amount of ion reducing agent added, a titration lid that controls the alkaline titration amount from fluctuations in acid concentration measured by an acid concentration measuring device, and a titration lid that controls the amount of each component in the sample solution from the titration curve. A quantitative analysis device for free acids and metal ions in a solution is provided, which is characterized by comprising a data processing device that performs quantitative value calculations and correction calculations.
以下に本発明をさらに詳細に説明する。The present invention will be explained in more detail below.
本発明は、前記問題点を解決するために、Ｆｅ”などの
ような滴定終点が酸の当量点と重複する金属イオンを含
む溶液において、金属イオンの還元時、吸光度検出法ま
たは電位差測定法により、還元反応の完了を検知し、還
元剤の添加量から、金属イオン濃度を求めた後、中和滴
定で遊ａｔ酸を定量する方法、さらに上記分析法を達成
するための溶液中遊離酸および金属イオン分析装置を開
発したことにある。In order to solve the above-mentioned problems, the present invention aims to solve the above problems by using an absorbance detection method or a potentiometric method during reduction of metal ions in a solution containing a metal ion such as "Fe" whose titration end point overlaps with the acid equivalent point. , a method of detecting the completion of the reduction reaction, determining the metal ion concentration from the amount of reducing agent added, and then quantifying the free acid by neutralization titration; The reason lies in the development of a metal ion analyzer.
還元剤としては、イソアスコルビン酸ナトリウム、チオ
硫酸ナトリウム、亜硫酸水素ナトリウムなどが挙げられ
る。 特にＦ ｅ ”の還元剤には、反応速度、副生成
物の妨害、ブランク値などの点から、イソアスコルビン
酸ナトリウムが好ましい。Examples of the reducing agent include sodium isoascorbate, sodium thiosulfate, and sodium hydrogensulfite. In particular, sodium isoascorbate is preferable as the reducing agent for F e '' in terms of reaction rate, interference with by-products, blank value, and the like.
■吸光光度法による還元反応完了の検出イソアスコルビ
ン酸ナトリウム添加によるＦｅ’ゝ還元時の吸光度の変
化を、吸収波長を変えて測定した結果を第１図に示す。(2) Detection of completion of reduction reaction by spectrophotometric method Figure 1 shows the results of measuring the change in absorbance during Fe' reduction due to the addition of sodium isoascorbate by changing the absorption wavelength.
このように還元の前後で溶液の吸光度が大きく変化し
、測定波長は３４０〜３８０ｎｍとするのが好ましいこ
とがわかる。It can thus be seen that the absorbance of the solution changes significantly before and after reduction, and that the measurement wavelength is preferably 340 to 380 nm.
■酸化還元電位による還元反応完了の検出イソアスコル
ビン酸ナトリウム添加によるＦｅ”還元時の酸化還元電
位の変化を第２図の■に、その微分曲線を同図の■に示
す。 変曲点Ａが電位変化の最大点を示しており、ここ
でＦｅ”の還元が完了している。 このように、溶液の
酸化還元電位の変化が大きく、このことを利用してＦｅ
’＋の還元反応の完了を検知でき、そのときの還元剤の
添加量により、Ｆｅ”濃度を求めることができる。■Detection of completion of reduction reaction by redox potential The change in redox potential during Fe” reduction due to the addition of sodium isoascorbate is shown in ■ in Figure 2, and its differential curve is shown in ■ in the same figure.The inflection point A is This shows the maximum point of potential change, at which point the reduction of Fe'' is completed. In this way, the change in the redox potential of the solution is large, and this can be used to
The completion of the '+ reduction reaction can be detected, and the Fe'' concentration can be determined from the amount of reducing agent added at that time.
また、鉄イオンを２価に還元することにより、鉄イオン
の滴定終点と遊離酸のそれを分離することができ、鉄イ
オン分析後、連続して中和滴定で遊離酸濃度を求めるこ
とが可能となる。 遊離酸の中和滴定には、水酸化ナト
リウム、水酸化カリウムなどのアルカリを用いればよい
。In addition, by reducing iron ions to divalent ions, it is possible to separate the iron ion titration end point from that of free acid, and after iron ion analysis, it is possible to determine the free acid concentration by continuous neutralization titration. becomes. For neutralization titration of free acids, an alkali such as sodium hydroxide or potassium hydroxide may be used.
本発明はまた、金属イオン含有液を純水で希釈し、酸の
当量点と滴定終点が重複する金属イオンを、溶液の吸光
度または酸化還元電位によって制御しながら還元し、還
元剤の滴定量から、金属イオン濃度を求めた後、中和滴
定により、遊離酸濃度を測定する装置を提供するもので
ある。The present invention also dilutes a metal ion-containing liquid with pure water, reduces metal ions whose titration end point overlaps the acid equivalent point while controlling the absorbance or redox potential of the solution, and calculates the titration amount of the reducing agent. , provides an apparatus for determining the metal ion concentration and then measuring the free acid concentration by neutralization titration.
本発明による分析装置の概略を第３図に示す。 試料溶
液槽１からバルブ２を通して、定量の試料溶液を希釈槽
３に導き、純水槽Ｊ ｈｌらポンプ５により純水で希釈
した後、金属イオンの還元剤６を添加する。 このとき
、吸光光度計または電位差計７からの信号により、制御
部８で制御されるパルスモータ−を使用した自動滴定装
置９により、還元剤を添加する。FIG. 3 shows an outline of the analyzer according to the present invention. A fixed amount of the sample solution is led from the sample solution tank 1 to the dilution tank 3 through the valve 2, diluted with pure water by the pure water tank pump 5, and then a metal ion reducing agent 6 is added. At this time, a reducing agent is added by an automatic titration device 9 using a pulse motor controlled by a control section 8 in response to a signal from an absorption photometer or a potentiometer 7.
続いて、アルカリ溶液槽１０から送られるアルカリ溶液
で中和滴定を行う。 このとき、酸濃度測定装置１１
からの信号により、制御部１２で制御されるパルスモー
タ−を使用した自動滴定装置１３でアルカリ溶液を添加
する。 なお、酸濃度測定装置としては、ｐＨ電極、吸
光光度計が適している。 得られたデータは、データ処
理装置１４で計算され、定量結果がプリンター１５に出
力される。 また、上記動作中は、溶液の混合を迅速
に行うため、攪拌装置１６を用いて溶液を攪拌する。
また、ガス吹込管１７で不活性ガス（窒素等）を希釈槽
に送り、攪拌中に金属イオンが酸化されるのを防ぐ。Subsequently, neutralization titration is performed using the alkaline solution sent from the alkaline solution tank 10. At this time, the acid concentration measuring device 11
An alkaline solution is added by an automatic titration device 13 using a pulse motor controlled by a control section 12 based on a signal from the controller 12 . Note that a pH electrode and an absorption photometer are suitable as the acid concentration measuring device. The obtained data is calculated by the data processing device 14, and the quantitative results are output to the printer 15. Further, during the above operation, the solution is stirred using the stirring device 16 in order to quickly mix the solution.
In addition, an inert gas (nitrogen, etc.) is sent to the dilution tank through a gas blowing pipe 17 to prevent metal ions from being oxidized during stirring.
酸洗液中の鉄イオンの滴定曲線は第２図のとおりである
。 また、ｐＨ電極による酸洗液中の遊離酸の滴定曲線
を第４図の■に、この微分曲線を同図の■に示す。The titration curve of iron ions in the pickling solution is shown in FIG. Further, the titration curve of the free acid in the pickling solution measured by the pH electrode is shown in ``■'' in FIG. 4, and its differential curve is shown in ``■'' in the same figure.
第２図の変曲点Ａは、イソアスコルビン酸ナトリウムに
よるＦｅ”の滴定終点である。 第４図の変曲点Ｂは、
遊離酸およびＦｅ’”還元時に生成する酸化型アスコル
ビン酸の中和点である。Inflection point A in Figure 2 is the end point of the titration of Fe'' with sodium isoascorbate. Inflection point B in Figure 4 is:
This is the neutralization point of free acid and oxidized ascorbic acid produced during Fe''' reduction.
Ｆｅ”″の還元剤にイソアスコルビン酸ナトリウムを用
いた場合、変曲点Ａ、Ｂでの滴定量をそれぞれａ、ｂと
すると、各成分濃度は、■式、■式により算出される。When sodium isoascorbate is used as a reducing agent for Fe"", and the titration amounts at inflection points A and B are respectively a and b, the concentration of each component is calculated by formulas (1) and (2).
また、吸光光度計による中和滴定は、ｐＨによって変色
する有色指示薬を添加し、溶液の吸光度の変化を検知す
ることにより、滴定終点を求めることができ、各成分濃
度は■式、■式により算出される。In addition, in neutralization titration using an absorption photometer, the titration end point can be determined by adding a colored indicator that changes color depending on the pH and detecting the change in the absorbance of the solution.The concentration of each component can be calculated using the formulas Calculated.
鉄イオン濃度（ｍｏｌ／ｕ）＝イソアスコルビン酸ナト
リウム水溶液の濃度（Ｎ）ｘａ （ｍｕ）ｘ２／試料分
取量〔ｍＩＬ〕 ・・・■′ｆｌｌ！ｌｌｔ酸濃度〔Ｎ
〕＝アルカリ液の濃度（Ｎ）ｘｂ（ｍｕ）／試料分取量
（ｍｊ２）−鉄イオン濃度（ｍ ｏ １ ／ ｆＬ ）
／ ２ ・・・■〈実施例〉
硝酸酸洗液中遊離酸および鉄イオンの定量について、具
体的な手順を以下に示す。Iron ion concentration (mol/u) = Concentration of sodium isoascorbate aqueous solution (N) xa (mu) x2/sample volume [mIL] ...■'fll! llt acid concentration [N
] = Concentration of alkaline solution (N) x b (mu) / Sample amount (mj2) - Iron ion concentration (m o 1 / fL)
/ 2...<Example> Specific procedures for quantifying free acid and iron ions in a nitric acid pickling solution are shown below.
遊離酸および鉄イオンの含有量が既知の合成液を用い、
本発明方法および従来の方法（片桐らの方法）を比較し
た。Using a synthetic solution with known free acid and iron ion contents,
The method of the present invention and a conventional method (Katagiri et al.'s method) were compared.
（実施例１）
全酸量５ｍｍｏｌ、金属イオン量０．５ｍｍｏ １程度
となるように、試料溶液（Ｎｏｌ）を１ｎＩ１分取し、
純水で５０ｍｆＬに希釈した。(Example 1) A sample solution (Nol) was taken in 1 nI portion so that the total acid amount was 5 mmol and the metal ion amount was about 0.5 mmol.
It was diluted to 50 mfL with pure water.
次に鉄イオンの還元剤であるイソアスコルビン酸ナトリ
ウム２％溶液を、３５０ｎｍにおける吸光度が０．０２
になるまで添加した。Next, a 2% solution of sodium isoascorbate, which is a reducing agent for iron ions, was added with an absorbance of 0.02 at 350 nm.
was added until
インアスコルビン酸ナトリウムの添加は、吸光度によっ
てその添加速度を制御しつつ行い、添加量は、２．１６
ｍｌ２であフた。Inascorbate sodium was added while controlling the addition rate based on absorbance, and the amount added was 2.16
It was cleaned with ml2.
鉄イオン還元終了後、直ちに０．２Ｎの水酸化ナトリウ
ム水溶液を用い、溶液ｐＨにより、添加速度を制御しつ
つ中和滴定を行った。 このときの水酸化ナトリウム水
溶液の添加量は７．１０ｍｌ２であった。Immediately after the iron ion reduction was completed, neutralization titration was performed using a 0.2N aqueous sodium hydroxide solution while controlling the addition rate depending on the pH of the solution. The amount of sodium hydroxide aqueous solution added at this time was 7.10 ml2.
（実施例２）
全酸ｆｆ１５ ｍ ｍ ｏ ｌ 、金属イオン量０．５
ｍｍｏ１程度となるように、試料溶液（Ｎｏｌ）を１ｍ
ＪＺ分取し、純水で５０ｍＩＬに希釈した。(Example 2) Total acid ff15 mmol, metal ion amount 0.5
Add 1 m of sample solution (Nol) to approximately 1 mmol.
JZ fraction was collected and diluted to 50 ml with pure water.
次に鉄イオンの還元剤であるイソアスコルビン酸ナトリ
ウム２％溶液で、酸化還元滴定を行った。 インアスコ
ルビン酸ナトリウムの添加は、溶液の酸化還元電位によ
ってその添加速度を制御しつつ行い、添加量は、２．ｊ
６ｍＡであった。Next, redox titration was performed using a 2% solution of sodium isoascorbate, which is a reducing agent for iron ions. Inascorbate sodium is added while controlling the addition rate depending on the redox potential of the solution, and the addition amount is 2. j
It was 6mA.
鉄イオン還元終了後、直ちに０．２Ｎの水酸化ナトリウ
ム水溶液を用い、メチルレッドを指示薬として溶液の吸
光度により、添加速度を制御しつつ中和滴定を行った。Immediately after the iron ion reduction was completed, neutralization titration was performed using a 0.2N aqueous sodium hydroxide solution while controlling the addition rate based on the absorbance of the solution using methyl red as an indicator.
このときの水酸化ナトリウム水溶液の添加量は７．１
０ｍｌ１であった。The amount of sodium hydroxide aqueous solution added at this time was 7.1
It was 0ml1.
（実施例３）
全酸量５ｍｍｏｌ、金属イオン量０．５ｍｍｏ １程度
となるように、試料溶液（Ｎｏ ２ ）を１ｍＪＺ分取
し、純水で５０ｍ℃に希釈した。(Example 3) A sample solution (No 2 ) was collected in 1 mJZ portion so that the total amount of acid was 5 mmol and the amount of metal ions was about 0.5 mmol, and diluted with pure water to 50 m°C.
次に鉄イオンの還元剤であるイソアスコルビン酸ナトリ
ウム２％溶液を、３５０ｎｍにおける吸光度が０．０２
になるまで添加した。Next, a 2% solution of sodium isoascorbate, which is a reducing agent for iron ions, was added with an absorbance of 0.02 at 350 nm.
was added until
イソアスコルビン酸ナトリウムの添加は、吸光度によっ
てその添加速度を制御しつつ行い、添加量は、ｔ、０８
ｍｕであった。Sodium isoascorbate was added while controlling the addition rate based on absorbance, and the addition amount was t, 08.
It was mu.
鉄イオン還元終了後、直ちに０．２Ｎの水酸化ナトリウ
ム水溶液を用い、溶液ｐＨにより、添加速度を制御しつ
つ中和滴定を行った。 このときの水酸化ナトリウム水
溶液の添加量は１１．３５ｍ！であった。Immediately after the iron ion reduction was completed, neutralization titration was performed using a 0.2N aqueous sodium hydroxide solution while controlling the addition rate depending on the pH of the solution. The amount of sodium hydroxide aqueous solution added at this time was 11.35 m! Met.
（実施例４）
全酸量５ｍｍｏｌ、金属イオン量０．５ｍｍｏｌ程度と
なるように、試料溶液（Ｎｏ ２ ）を１ｍ℃分取し、
純水で５０ｍｆ１．に希釈した。(Example 4) A sample solution (No.
50mf1. with pure water. diluted to
次に鉄イオンの還元剤であるイソアスコルビン酸ナトリ
ウム２％溶液で、酸化還元１＾定を行った。 イソアス
コルビン酸ナトリウムの添加は、溶液の酸化還元電位に
よってその添加速度を制御しつつ行い、添加量は、１．
０８ｍＩＬであった。Next, redox 1^ determination was performed using a 2% solution of sodium isoascorbate, which is a reducing agent for iron ions. Sodium isoascorbate is added while controlling the addition rate depending on the redox potential of the solution, and the amount added is 1.
It was 08 mIL.
鉄イオン還元終了後、直ちに０．２Ｎの水酸化ナトリウ
ム水溶液を用い、メチルレッドを指示薬として溶液の吸
光度より、添加速度を制御しつつ中和滴定を行った。
このときの水酸化ナトリウム水溶液の添加量は１１．３
５ ｍ ｊ２であった。Immediately after the iron ion reduction was completed, neutralization titration was performed using a 0.2N aqueous sodium hydroxide solution while controlling the addition rate based on the absorbance of the solution using methyl red as an indicator.
The amount of sodium hydroxide aqueous solution added at this time was 11.3
It was 5 m j2.
（比較例１）
従来の方法を用い、前記実施例１．２と同じ試料溶液（
Ｎｏｌ）の定量分析を行った。(Comparative Example 1) Using the conventional method, the same sample solution as in Example 1.2 (
Quantitative analysis was performed.
すなわち、試料溶液（Ｎｏ、１）１ｍＪ２を純水で５０
ｍＪ：Ｌに希釈し、これに１ ｍ ｏ １ ／ ｆｌ、
のチオ硫酸ナトリウム０．１ｍ℃を加え、Ｆｅ”の還元
を行った。 その後、０．２Ｎ水酸化ナトリウム水溶液
で溶液ＰＨにより添加速度を制御しつつ滴定し、遊離酸
および鉄イオンを分析した。That is, 1 mJ2 of the sample solution (No. 1) was mixed with pure water at 50%
Dilute to mJ:L, add 1 m o 1/fl to this,
0.1 m°C of sodium thiosulfate was added to reduce Fe". Thereafter, titration was performed with a 0.2N aqueous sodium hydroxide solution while controlling the addition rate depending on the pH of the solution, and free acid and iron ions were analyzed.
このとき、遊離酸の変曲点における水酸化ナトリウム水
溶液の添加量は １０．３５ｍ Ｉｔであり、鉄イオン
の変曲点における水酸化ナトリウム水溶液の添加量は、
目、２５ｍｊ２であった。At this time, the amount of sodium hydroxide aqueous solution added at the inflection point of the free acid is 10.35 mIt, and the amount of sodium hydroxide aqueous solution added at the inflection point of iron ions is:
It was 25mj2.
（比較例２）
従来の方法を用い、前記実施例３．４と同じ試料溶液（
Ｎｏ２）の定量分析を行った。(Comparative Example 2) Using the conventional method, the same sample solution as in Example 3.4 (
No. 2) was quantitatively analyzed.
すなわち、試料溶液（Ｎｏ、２）１ｍ℃を純水で５０ｍ
ＪＺに希釈し、これに１ ｍ ｏ １ ／ ｉｔのチオ
硫酸ナトリウム１．０ｍ１ｔを加え、Ｆｅ”の還元を行
った。 その後、０．２Ｎ水酸化ナトリウム水溶液で溶
液ｐＨにより添加速度を制御しつつ滴定し、遊離酸およ
び鉄イオンを分析した。That is, sample solution (No. 2) was heated at 1 m℃ with pure water for 50 m
JZ and 1.0 ml of 1 m o 1/it sodium thiosulfate was added thereto to reduce Fe''. Thereafter, with a 0.2N aqueous sodium hydroxide solution, the addition rate was controlled by the solution pH. Titrated and analyzed for free acid and iron ions.
このとき、遊離酸の変曲点における水酸化ナトリウム水
溶液の添加量は １０．０５ｍ １１であり、鉄イオン
の変曲点における水酸化ナトリウム水溶液の添加量は、
１２．０５ｍＪ１であった。At this time, the amount of sodium hydroxide aqueous solution added at the inflection point of the free acid is 10.05 m 11, and the amount of sodium hydroxide aqueous solution added at the inflection point of iron ions is:
It was 12.05mJ1.
実施例および比較例において、滴定時の終点付近での急
激な電位、吸光度またはｐＨの変化を正確にとらえるた
め、終点直前では、滴定液の添加速度を遅くした。In Examples and Comparative Examples, in order to accurately capture sudden changes in potential, absorbance, or pH near the end point during titration, the addition rate of the titrant was slowed just before the end point.
本発明および従来の方法による合成液の分析結果を第２
表に示す。 従来法では、Ｆｅ”の還元剤添加量が不足
すると、残留Ｆ ｅ ”により、Ｎｏ １のように鉄が
低値を示し、その減少分の３倍量分、遊離酸濃度が高値
となる。 また、還元剤添加量が過剰の場合、Ｎｏ２の
ように遊Ｉ１１酸濃度が低値を示す。 しかし、本発明
によれば、従来法に比べ、遊離酸、鉄イオンともに、
定量値は添加量と良い一致を示してい
る。The analysis results of the synthetic liquid according to the present invention and the conventional method are
Shown in the table. In the conventional method, when the amount of Fe'' reducing agent added is insufficient, iron shows a low value as in No. 1 due to residual Fe'', and the free acid concentration increases by three times the amount of the decrease. Further, when the amount of reducing agent added is excessive, the free I11 acid concentration shows a low value as in No. 2. However, according to the present invention, compared to the conventional method, the quantitative values of both free acid and iron ions show good agreement with the amount added.
第
表
（ｍｏｌ／４２）
〈発明の効果〉
本発明によれば、溶液中の遊離酸および金属イオンを正
確に分析することが可能となる。 また、測定の自動化
、あるいは現場での管理分析への対応が容易である。
例えば、酸洗液中の遊離酸および金属イオン濃度を細か
く設定することが可能となり、製品の安定生産、コスト
の低減を図ることが可能である。Table 1 (mol/42) <Effects of the Invention> According to the present invention, it becomes possible to accurately analyze free acids and metal ions in a solution. In addition, it is easy to automate measurements or perform on-site management analysis.
For example, it becomes possible to finely set the free acid and metal ion concentrations in the pickling solution, and it is possible to achieve stable product production and cost reduction.
第１図は、Ｆｅ”還元時の吸光度の変化を吸収波長を変
えて測定したグラフである。
第２図は、Ｆｅ’″″還元時の溶液の酸化還元電位の変
化を測定したもの■、およびその微分曲線■を示すグラ
フである。
第３図は、本発明による分析装置の概略図である。
第４図は、酸洗液中の遊離酸の滴定曲線■およびその微
分曲線■を示すグラフである。
符号の説明
１・・・試料溶液槽、
２・・・バルブ、
３・・・希釈槽、
４・・・純水槽、
５・・・ポンプ、
６・・・還元溶液槽、
７・・・吸光光度計または電位差計、
８・・・制御部、
９・・・自動滴定装置、
１０・・・アルカリ溶液槽、
１１・・・酸濃度測定装置、
１２・・・制御部、
１３・・・自動滴定装置、
１４・・・データ処理装置、
１５・・・プリンター
１６・・・攪拌装置、
１７・・・ガス吹込管
Ｇ、 １
波
長
（ｎｍ）
Ｇ、２
酸
化
還
冗
位
Ｘ
Ｇ、３
■
０．４
ＨFigure 1 is a graph of changes in absorbance during Fe''' reduction measured by changing the absorption wavelength. Figure 2 is a graph showing measurements of changes in redox potential of the solution during Fe'''' reduction. FIG. 3 is a schematic diagram of an analyzer according to the present invention. FIG. 4 is a graph showing a titration curve (■) of free acid in a pickling solution and its differential curve (■). It is a graph. Explanation of symbols 1... Sample solution tank, 2... Valve, 3... Dilution tank, 4... Pure water tank, 5... Pump, 6... Reducing solution tank, 7 ...Absorption photometer or potentiometer, 8.Control unit, 9.Automatic titration device, 10.Alkaline solution tank, 11.Acid concentration measuring device, 12.Control unit, 13 ...Automatic titration device, 14...Data processing device, 15...Printer 16...Stirring device, 17...Gas blowing pipe G, 1 Wavelength (nm) G, 2 Redox redundancy X G , 3 ■ 0.4 H
Claims (2)
む溶液において、吸光度検出法または電位差測定法によ
り、金属イオンの還元反応の完了を検知し、還元剤の添
加量から金属イオン濃度を求めた後、中和滴定により遊
離酸濃度を求めることを特徴とする溶液中遊離酸および
金属イオンの連続定量分析法。(1) In a solution containing a metal ion whose titration end point overlaps with the acid equivalence point, the completion of the reduction reaction of the metal ion is detected by absorbance detection method or potentiometry, and the metal ion concentration is determined from the amount of the reducing agent added. A continuous quantitative analysis method for free acids and metal ions in a solution, which comprises determining the free acid concentration by neutralization titration after determining the free acid concentration.
された試料溶液の希釈装置と、吸光光度計または電位差
計により測定される吸光度または電位の変動から金属イ
オン還元剤の添加量を制御する還元剤添加装置と、酸濃
度測定装置により測定される酸濃度の変動からアルカリ
滴定量を制御する滴定装置と、滴定曲線から試料溶液中
の各成分の定量値計算、補正計算を行うデータ処理装置
とを具えることを特徴とす る溶液中遊離酸および金属イオンの定量分析装置。(2) A sample solution diluter equipped with an absorption photometer or potentiometer and a pH electrode, and reduction in which the amount of metal ion reducing agent added is controlled based on the absorbance or potential variation measured by the absorption photometer or potentiometer. a titration device that controls the alkali titer based on fluctuations in the acid concentration measured by the acid concentration measurement device, and a data processing device that calculates the quantitative values of each component in the sample solution from the titration curve and performs correction calculations. 1. A quantitative analysis device for free acids and metal ions in a solution, comprising:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1090250A JP2530711B2 (en) | 1989-04-10 | 1989-04-10 | Method and apparatus for simultaneous quantitative analysis of free acid and ferric ion in solution |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1090250A JP2530711B2 (en) | 1989-04-10 | 1989-04-10 | Method and apparatus for simultaneous quantitative analysis of free acid and ferric ion in solution |
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| Publication Number | Publication Date |
|---|---|
| JPH02268271A true JPH02268271A (en) | 1990-11-01 |
| JP2530711B2 JP2530711B2 (en) | 1996-09-04 |
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|---|---|---|---|
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| CN102680555A (en) * | 2012-03-31 | 2012-09-19 | 武汉钢铁(集团)公司 | Method for measuring free acid concentration in acid liquid |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR19990052840A (en) * | 1997-12-23 | 1999-07-15 | 이구택 | On-line Analysis System of Trace Metal Ions in Electro-Zinc Plating Solution Using Potentiometric Method |
| CN103616471A (en) * | 2013-11-22 | 2014-03-05 | 安徽华业香料股份有限公司 | Detection method for esterification reaction in production process of hexyl salicylate |
| CN105944785A (en) * | 2016-04-28 | 2016-09-21 | 安庆市峰邦工业产品设计有限公司 | Special purification device for acid-base titration |
| JP2022510518A (en) * | 2019-07-15 | 2022-01-27 | 王飛 | Spectral potential temperature multidimensional titration analyzer and its usage |
| CN113252660A (en) * | 2021-05-13 | 2021-08-13 | 中航金属材料理化检测科技有限公司 | Method for analyzing chemical component content of high-temperature alloy corrosive liquid |
| CN113759073A (en) * | 2021-09-26 | 2021-12-07 | 山西沁新能源集团股份有限公司 | Analysis and detection method for multiple components in waste liquid or recovery liquid of mixed acid |
| CN114544882A (en) * | 2022-03-07 | 2022-05-27 | 新疆西部合盛硅业有限公司 | Novel method for on-line monitoring of acid-base concentration of material |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2530711B2 (en) | 1996-09-04 |
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